Cockles, barnacles and ascidians compose a subtidal facilitation cascade with multiple hierarchical levels of foundation species.

ABSTRACT: Facilitation cascades occur when multiple foundation species in a community are involved in a hierarchy of positive interactions, and consist of a primary facilitator which positively affects secondary facilitators, each supporting a suit of dependent species. There is no theoretical limit to the number of levels in a facilitation cascade, yet the existence of more than two has rarely been examined. We manipulated biogenic substrate produced by a primary facilitator (cockle shells) and a secondary facilitator (barnacles and their empty tests) in a space-limited subtidal community to test the hypothesis that solitary ascidians would be the third-level facilitator. In the field, most ascidians were found on barnacles, and most barnacles occupied cockle shells. To produce this pattern, barnac

SUBMITTER: Yakovis E 

PROVIDER: S-EPMC5427999 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature